Esters of 5-tertiarybutylsalicylic acid



Patented Mar. 8, 1949 UNITED STATES PATENT OFFICE Edgar C. Britten and Ezra Monroe, Midland,

Mich, assignors to The Dow Chemical Company, Midland, Mich, a corporation of Delaware No Drawing. Application August 23, 1947,

Serial No. 770,326

4 Ciaims. 1 This invention relates to novel esters of -tertiarybutylsalicylic acid having the general formula where Y is a member of the group consisting of tertiaryalkyl, aryl, and halogen.

Representative members of this class of compounds have been prepared and identified, and found valuable as intestinal antiseptics and for other medicinal uses. They are also useful as modifying agents for vinylidene chloride polymers and copolymers, nitrocellulose, cellulose acetate and cellulose esters. The compounds are substantially non-volatile at room temperature, readily soluble in the solvents and solvent mixtures commonly employed for dissolving cellulose derivatives, and stable to light.

The new esters may be prepared by any of the conventional esterification methods. One satisfactory procedure comprises heating 5-tertiarybutylsalicylic acid with a molecular equivalent of a tertiaryalky1-, aryl-, or monohalophenol to a temperature above 100 C. and preferably to a temperature between about 120 C. and about 150 C., in the presence of phosphorus oxychloride. The mixture is stirred during the reaction period. The esterification is usually complete in from about 1 to 5 hours, although a longer period may sometimes be required. Upon substantial completion of the reaction, the crude product is treated with sufficient aqueous alkali to neutralize unreacted acid therein. The oily product of reaction is thereafter separated as by decantation, and purified either by fractional distillation under vacuum or by crystallization from a suitable solvent such as chlorobenzene, alcohol, or mixtures thereof.

The following examples illustrate the invention but are not to be construed as limiting.

Example 1 98.5 grams (0.5 mol) of S-tertlarybutylsalicylic acid, melting at 154 C., and 75 grams (0.5 mol) of -tertiarybutylphenol were placed in a three-neck glass flask equipped with a stirrer, thermometer, condenser, and dropping funnel. The flask was heated in an oil bath until the temperature of the reaction mixture was 110 C. 42 grams (0.27 mol) of phosphorus oxychloride was then slowly added through the dropping funnel while continuously stirring the mixture. Copious fumes of hydrochloric acid were evolved during the reac* tion. The mixture was stirred and heated at ll0-125 C. for two hours, and thereafter poured into water. This crude aqueous mixture was extracted with 300 milliliters of benzene. The benzene extract was separated, washed successively with dilute aqueous sodium carbonate and water, dried, and the benzene recovered by distillation. The residue, consisting of 38 grams of crude prodnot, was recrystallized from a mixture of two parts chlorobenzene and one part ethyl alcohol. 26 grams of 4-tertiarybutylphenyl 5-tertiarybutylsalicylate was thereby obtained as white crystals melting at approximately 155 C. and having the formula Example 2 In a similar manner 4-tertiaryamylphenol was reacted with 5-tertiarybutylsalicylic acid to obtain 4-tertiaryamylpheny1 5-tertiarybutylsalicylate as a white crystalline solid melting at -107 C. and having the formula Example 3 -chlorophenol was reacted with 5-tertiarybutylsalicylic acid substantially as described in Example 1 to obtain -chlorophenyl 5-tertiarybutylsalicylate as a white crystalline solid melting at 68-70 C. and having the formula Eaample 4 Similarly l-xenol (4-hydroxy-diphenyl) was reacted with 5-tertiarybutylsalicylic acid to ob- 3 tain 5-xenyl 5-tertiarybutylsa1icylate as a white crystalline solid melting at 162165 C. and having the formula CH CH In like manner, E-tertiarybutylsalicylic acid may be reacted with other phenols according to the herein described procedure. Representative of the compounds so obtained are4-br0mophenyl 5-tertiarybutylsalicylate, -iodophenyl 5-tertiarybutylsalicylate, 2-xenyl 5-tertiarybutylsalicylate, 3-Xenyl 5-tertiarybutylsalicylate, 4-tertiaryoctylphenyl 5-tertiarybutylsalicylate, 2-tertiarybuty1- phenyl 5-tertiarybutylsa1icy1ate, 2-chlorophenyl 5-tertiarybutylsalicylate and 3-ch1orophenyl 5- tertiarybutylsalicylate.

The vpresent application is a continuation-inpart of a co-pending application, Serial No. 438,- 439, filed April 10, 1942, which has become abandoned.

We claim:

1. An ester of 5-.tertiarybutylsalicylic acid having the formula if Q G wherein Y is a member'of the group consisting of tertiaryalkyl, phenyl and chlorine.

2. 4-tertiarybutylphenyl 5-tertiarybutylsalicylate, a White crystalline solid having a melting point of approximately 155 C. and the formula CH; CHa--CH 0 CH3 4 3. 4-chlorophenyl 5-tertiarybutylsalicylate, a white crystalline solid having a melting point of 68-70 C. and the formula OH CH;

EDGAR C. BRITTON. EZRA MONROE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Name Date Mills et a1 May 3, 1932 Bass et a1 Sept. 6, 1938 Britton et a1. Jan. 8, 1946 FOREIGN PATENTS Country Date Germany Mar. 22, 1893 Germany July 25, 1893 OTHER REFERENCES Dobrzyski, J ourn. fiir Praktische Chemie (2) vol. 36, page 396 (1887).

Meyer et a1., Monatshifte fiir Chemie, vols. 53 and 54, pages 721-752 (1929).

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